Well is he just working a lot? Is that why you say he's not supportive?
Maybe u need to sit and talk with him about his feelings maybe he really isn't happy or maybe he is or maybe he just shocked talk to him and ask
Have you talked to him about it? Lots of guys don't know how to be emotionally supportive during pregnancy, because they're not experiencing things first hand. I know my partner was being really distant, because he was freaking out about becoming a father and he didn't want to upset me, and he eventually snapped and told me exactly how he was feeling. I've been hyper sensitive to emotions lately, so I found that really hard to take from him. If your guy seems distant, it could be because he doesn't want to upset you while he works out in his head what becoming a father means. I'm not saying it's a good strategy, I'm just saying it's one possibility. I would talk to him if I were you. Try to get him involved by inviting him baby shopping g and to patenting classes and stuff.